protected volatile boolean valid;
    
    public RdmaMemoryRegion(ByteBuffer buffer, EnumSet<RdmaAccess> access) {
        this.buffer = buffer;
        this.accessFlags = access;
        this.localKey = generateLocalKey();
        this.remoteKey = generateRemoteKey();
        this.address = getBufferAddress(buffer);
        this.valid = true;
    }
    
    public ByteBuffer getBuffer() {